This invention relates to a oculistics pharmaceutical composition which comprises thyroid hormones and a process for extraction of thyroid hormones from powder of domesticated animals thyroid. The pharmaceuticals of this invention is used to treat cataracts and specifically to treat senile cortical cataracts with special effect.
The use of thyroid hormones to treat cretinism, myxedema nontoxic goiter in which thyroid function is either diminished or absent is already known. thyroid preparation also have been used in patients with normal thyroid function in the treatment of obesity. (Charles R. Craig, Robert E. Stitzel, Modern pharmacology, P. 862-865, 1982) According to the principle of thyroid hormones stimulating the metabolism, development and growth of organism, thyroid hormones are absorbed by many tissues and specifically L-3,5,3'-triiodothyronine. L-3,5,3'-triiodothyronine is 3 to 5 times more active than L-3,5,3',5'-tetraiodothyronine. The conversion of L-3,5,3',5'-tetraiodothyronine to L-3,5,3'-triiodothyronine represents a process of hormone activation in peripheral monodeiodination. Charles R. Craig, Robert E. Stitzel, Modern Pharmacology, page 862 (1982). L-3,5,3'-triiodothyronine has a relatively rapid onset of action, but its peak effect and duration of action are shorter than L-3,5,3',5'-tetraiodothyronine. In accordance with the invention it has been discovered that the local application of thyroid hormones to treat cataracts results in remarkable beneficial effect. The senile cataract is by far the most common type and the causes are unknown but are usually associated with aging. Senile changes of some degree occur in the lens, as in all other tissues. These changes are of universal occuraence and must be considered physiological, their intensity and the date of their onset being determined partly by hereditary and constitutional factors and partly the stresses imposed by environmental conditions. Stewart Duke, Textbook of Opthamology, Chapter VIII, Diseases of the Inner Eye, pages 3177-3181. Many opthalmologist have considered that the lens aging is a basis of senile cataract. Metabolism is decreased and new fibers are decreased in an aging lens. The invention has discovered that thyroid hormones can be used effectively for the treatment of patients with senile cataract. Until now, the treatment for cataract has been by operation, but such an operation causes the patient to suffer and it is expensive in cost. Ophthalmologists and patients have saught a medical treatment for cataracts to delay or avoid the cataract surgery. Those investigation and exploration are progressing in many countries. Many medicinal treatments and therapies were introduced in China and in other countries. Among the drugs employed the most common, and one of the oldest remedies proposed, was iodine. Various vitamines, various hormones (a mixture of thyroid, parathyroid, gonad extracts was advanced by Siegrist "Der Grave Alterstar berlin" 1928), Phacolysin, catalin, and tathione etc. also have been employed. As a matter of fact the clinical effect on senile cataract with medical treatment have not been well known.
In published Japan Pat. No. 53-86009 Thyrotropin-releasing hormone (TRH) with medical carrier was prepared to a oculistic pharmaceuticals to treat for cataract had been disclosed.
The means of a biochemical for extraction of thyroid hormones had been disclosed in "Biochemical J." Harington, U.S.A. (1926), Vol. 20, p. 293; J. Gross, "Biochemical J." (1953), Vol, 54, P. 645-650.
In U.S. Pat. Nos. 3,705,142 and 3,455,894 and 3,674,770 the method of synthesizing L-3,5,3'-triiodothyronine and L-3,5,3',5'-tetraiodothyronine had been disclosed.